This is a post by Aaron Shaw on PTC site.
Welds created in Creo Parametric establish the geometry and location of welds in your assembly, but you must have weld features to perform analysis and simulation using Creo Simulate. Now, the system can detect solid weld types and automatically create weld features in Creo Simulate. Here’s how:
Automatically Detect Welds
Open up a model that includes welds that you want to analyze.